@article {Ferrara220,
author = {Ferrara, Assiamira and Barrett-Connor, Elizabeth and Wingard, Deborah L and Edelstein, Sharon L},
title = {Sex Differences in Insulin Levels in Older Adults and the Effect of Body Size, Estrogen Replacement Therapy, and Glucose Tolerance Status: The Rancho Bernardo Study, 1984{\textendash}1987},
volume = {18},
number = {2},
pages = {220--225},
year = {1995},
doi = {10.2337/diacare.18.2.220},
publisher = {American Diabetes Association},
abstract = {OBJECTIVE To determine if insulin levels vary with sex, independent of estrogen replacement therapy (ERT), differences in body mass index (BM1), waist-to-hip ratio (WHR), and glycernia. RESEARCH DESIGN AND METHODS In a population-based study of older adults, insulin levels were measured before and after a standardized oral glucose tolerance test in 673 men and 849 women, all free of known diabetes. RESULTS Age-adjusted fasting insulin levels were highest in men, intermediate in women not taking estrogen, and lowest in estrogen-treated women (P \< 0.01). Differences between men and women not taking estrogen disappeared after adjusting for age and BMI, but not glycemia; estrogen-treated women had significantly lower fasting insulin levels than did men (P \< 0.01) and women not taking estrogen (P \< 0.01). The association of estrogen use with lower fasting insulin levels persisted after adjusting for age and WHR (P \< 0.001) and was stronger among women with abnormal glucose tolerance. Age-adjusted postchallenge insulin levels were higher in women than in men (P \< 0.01). The sex difference persisted after adjusting for age and BMI or glycemia. Postchallenge insulin levels did not vary by ERT. CONCLUSIONS Men have higher fasting insulin levels than do women, whether or not the women are using ERT. Differences between men and untreated women are explained by differences in BMI, but estrogen users have lower fasting insulin levels independent of BMI. Postchallenge insulin levels are higher in women than men and are independent of ERT, BMI, and glycemia. Clinical trials in women are needed to determine whether ERT can improve insulin and glucose metabolism.},
issn = {0149-5992},
URL = {http://care.diabetesjournals.org/content/18/2/220},
eprint = {http://care.diabetesjournals.org/content/18/2/220.full.pdf},
journal = {Diabetes Care}
}